Mobile wireless communication devices, such as a cellular telephone or a wireless personal digital assistant, can provide a wide variety of communication services including, for example, voice communication, text messaging, internet browsing, and electronic mail. Mobile wireless communication devices can operate in a wireless communication network of overlapping “cells”, each cell providing a geographic area of wireless signal coverage that extends from a radio network subsystem located in the cell. The radio network subsystem can include a base transceiver station (BTS) in a Global System for Communications (GSM) network or a Node B in a Universal Mobile Telecommunications System (UMTS) network. The radio network subsystem can also be referred to as a radio access network in a Code Division Multiple Access (CDMA) network and can include a BTS.
The mobile wireless communication device can receive signals transmitted from one or more cells in the wireless communication network. The radio network subsystems in each of the cells can be located at different distances from the mobile wireless communication device, and therefore signals received at the mobile wireless communication device can vary in signal strength and/or signal quality. The mobile wireless communication device can measure and monitor the received signals to determine to which cells a connection can be achieved and maintained. Together with one or more radio network subsystems in the wireless communication network, the mobile wireless communication device can select to which cells to connect and disconnect as the mobile wireless communication device moves throughout the wireless network.
The mobile wireless communication device can be connected to one or more cells in the wireless communication network simultaneously. Measurement messages (or more generally management messages) can be transmitted by the mobile wireless communication device to the wireless communication network informing the wireless communication network of changes to radio frequency signal conditions observed by the mobile wireless communication device. Certain messages transmitted by the mobile wireless communication device can require acknowledgement from the wireless communication network before the mobile wireless communication device considers their transmission complete. Messages that do not receive an acknowledgement from the wireless communication network can be retransmitted by the mobile wireless communication device in order to ensure their correct reception by the wireless communication network. Multiple retransmissions of a message to the wireless communication network from the mobile wireless communication device without an attendant acknowledgement being received by the mobile wireless communication device can ultimately result in termination of one or more connections between the mobile wireless communication device and the wireless communication network.
Multiple connections between the mobile wireless communication device and radio network subsystems located in one or more cells in the wireless communication network can be used for different services, such as for simultaneous voice and data, as well as for diversity during handoff between cells as the mobile wireless communication device traverses the wireless communication network. Measurement messages for each of the multiple connections can be sent to the wireless communication network to indicate changes in received radio frequency signal conditions at the mobile wireless communication device. When the received radio frequency signals at the mobile wireless communication device can change rapidly, a measurement message sent by the mobile wireless communication device to the wireless communication network previously can become obsolete before an acknowledgement to the measurement message has been received at the mobile wireless communication device. When no acknowledgement has been received, the mobile wireless communication device can continue to retransmit the obsolete message to the wireless communication network. Retransmission by the mobile wireless communication device can prove counterproductive, as the information conveyed in the measurement message can be supplanted by new measurements of signals received at the mobile wireless communication device. When repeated re-transmissions of a message are sent without acknowledgements being received by the mobile wireless communication device from the wireless communication network, termination of one or more connections between the mobile wireless communication device and the wireless communication network can occur. This termination of connections can be unnecessary, as the information being conveyed by the retransmissions can be obsolete.
Thus there exists a need to control measurement messaging between a mobile wireless communication device and a wireless communication network during dynamically changing network conditions.